Relativistic femtosecond mid-infrared pulses can be generated efficiently by laser interaction with near-criticaldensity plasmas.It is found theoretically and numerically that the radiation pressure of a circularly po...Relativistic femtosecond mid-infrared pulses can be generated efficiently by laser interaction with near-criticaldensity plasmas.It is found theoretically and numerically that the radiation pressure of a circularly polarized laser pulse first compresses the plasma electrons to form a dense flying mirror with a relativistic high speed.The pulse reflected by the mirror is red-shifted to the mid-infrared range.Full three-dimensional simulations demonstrate that the central wavelength of the mid-infrared pulse is tunable from 3µm to 14µm,and the laser energy conversion efficiency can reach as high as 13%.With a 0.5–10 PW incident laser pulse,the generated mid-infrared pulse reaches a peak power of 10–180 TW,which is interesting for various applications in ultrafast and high-field sciences.展开更多
In this paper,the Dyakonov-Shur instability of terahertz(THz)plasma waves has been analyzed in gated cylindrical field effect transistor(FET).In the cylindrical FET,the hydrodynamic equations in cylindrical coordinate...In this paper,the Dyakonov-Shur instability of terahertz(THz)plasma waves has been analyzed in gated cylindrical field effect transistor(FET).In the cylindrical FET,the hydrodynamic equations in cylindrical coordinates are used to describe the THz plasma wave in twodimensional electronic gas.The research results show that the oscillation frequency of the THz plasma wave is increased by increasing the component of wave in the circumferential direction,but in stability increment of the THz plasma wave are in creased by increasing the radius of channel.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.12375244,12135009,and 12275356)the Hunan Provincial Innovation Foun-dation for Postgraduate(Grant Nos.CX20210062 and CX20230006).
文摘Relativistic femtosecond mid-infrared pulses can be generated efficiently by laser interaction with near-criticaldensity plasmas.It is found theoretically and numerically that the radiation pressure of a circularly polarized laser pulse first compresses the plasma electrons to form a dense flying mirror with a relativistic high speed.The pulse reflected by the mirror is red-shifted to the mid-infrared range.Full three-dimensional simulations demonstrate that the central wavelength of the mid-infrared pulse is tunable from 3µm to 14µm,and the laser energy conversion efficiency can reach as high as 13%.With a 0.5–10 PW incident laser pulse,the generated mid-infrared pulse reaches a peak power of 10–180 TW,which is interesting for various applications in ultrafast and high-field sciences.
文摘In this paper,the Dyakonov-Shur instability of terahertz(THz)plasma waves has been analyzed in gated cylindrical field effect transistor(FET).In the cylindrical FET,the hydrodynamic equations in cylindrical coordinates are used to describe the THz plasma wave in twodimensional electronic gas.The research results show that the oscillation frequency of the THz plasma wave is increased by increasing the component of wave in the circumferential direction,but in stability increment of the THz plasma wave are in creased by increasing the radius of channel.
